In the bookbinding art collated pages of a book are clamped in a conveyor and passed over an adhesive applicator, known in the art as a glue pot, holding a supply of adhesive. The adhesive is carried from the pot by one or more rolls partially immersed in the glue pot up to a gluing plane through which the backbone of the book is conveyed. In older gluers doctor blades control the amount of glue carried by the rolls to the gluing plane, but there is a need in modern high speed equipment not only to control the glue applied but to confine it against overflowing the glue pot as a result pf pumping of the glue by the rolls to the ends of the pot.
Accordingly one object of the present invention is to prevent overflow in high speed applicator. A related object is to provide a way of metering application of glue in linear relation to a metering adjustment.